I very strongly recommend Hancock's book "Supernatural." It explores the question of DMT/ayahuasca transdimensional hyperspace traveling and what it may be all about. Hancock shows the vast commonalities in peoples' experiences with DMT and with ancient shamanic art, and how much they all match up. Incredible book.
Here's a longer slide presentation, in which he gets into some of the substance from Supernatural:
http://www.youtube.com/watch?v=0qgMFO0KU-I

You mean "Supernatural"? Awesome! One of the very best psychedelic books I've ever read. The other is "The Cosmic Serpent," by Jeremy Narby, which posits an actual workable scientific theory based around DNA for what happen in deep DMT and ayahuasca experiences (Hancock references it). If you feel like it, let me know what you think when you're done.